Multi-energy ion implantation

ABSTRACT

In a multi-energy ion implantation process, an ion implanting system having an ion source, an extraction assembly, and an electrode assembly is used to implant ions into a target. An ion beam having a first energy may be generated using the ion source and the extraction assembly. A first voltage may be applied across the electrode assembly. The ion beam may enter the electrode assembly at the first energy, exit the electrode assembly at a second energy, and implant ions into the target at the second energy. A second voltage may be applied across the electrode assembly. The ion beam may enter the electrode assembly at the first energy, exit the electrode assembly at a third energy, and implants ions into the target at the third energy. The third energy may be different from the second energy.

BACKGROUND

1. Field

This relates generally to semiconductor processing and, morespecifically, to methods for multi-energy ion implantation.

2. Related Art

Ion implantation is an important process in the production of integratedsemiconductor devices where dopant ions such as boron, phosphorus,arsenic or the like are implanted into a semiconductor substrate tomodify the conductivity of the substrate. Certain applications, such asthe doping of semiconductor fin structures in the fabrication of FinFETdevices, may require a multi-energy ion implantation process to achievedesirable uniformity and thus desirable device performance. In amulti-energy ion implantation process, an ion implanting system performsa set of implants on a target (e.g., a semiconductor wafer having asemiconductor device formed thereon) where each implant is performed ata different energy.

Conventionally, the implant energy for a multi-energy ion implantationprocess is controlled by adjusting the ion source and the extractionassembly conditions. For example, the implant energy may be increased byincreasing the extraction voltage while increasing the distance betweenthe ion source and the extraction electrode. Additionally, the dopantgas flow rate and the source magnetic field may be adjusted to achievethe desired ion beam current. Adjusting the ion source and extractionassembly conditions optimizes the ion beam current for each implant,thereby extending the life of the ion source. However, changing the ionsource and extraction assembly conditions also destabilizes the ion beamwhere the ion beam requires up to several minutes to re-tune andre-stabilize before it can be used to implant ions into a target. Inorder to reduce the frequency at which the ion source and extractionassembly conditions are changed, conventional multi-energy ionimplantation processes may, for example, implant every target in aproduction lot at a first energy prior to changing the ion beam to asecond energy. Each target in the same production lot may then beimplanted at the second energy. However, target handling times areincreased because each target is transferred into and out of the ionimplanting system for each implant energy. Thus, conventionalmulti-energy ion implantation suffers from low throughputs and may notbe a manufacturable solution for semiconductor device production.

BRIEF SUMMARY

In one exemplary embodiment, an ion implanting system having an ionsource, an extraction assembly, and an electrode assembly is used formulti-energy ion implantation into a target. An ion beam having a firstenergy and a first current may be generated using the ion source and theextraction assembly. A first voltage may be applied across the electrodeassembly. The ion beam may enter the electrode assembly at the firstenergy, exit the electrode assembly at a second energy, and implant ionsinto the target at the second energy. The second energy may be differentfrom the first energy. A second voltage may be applied across theelectrode assembly. The ion beam may enter the electrode assembly at thefirst energy, exit the electrode assembly at a third energy, andimplants ions into the target at the third energy. The third energy maybe different from the second energy.

The ion implant system may additionally have a variable aperture tocontrol the implant current. The ion beam may be directed through thevariable aperture prior to implanting the target. While applying a firstvoltage across the electrode assembly, the variable aperture may be setto a first aperture width where ions may be implanted into the target ata second energy and a second current. While applying a second voltageacross the electrode assembly, the variable aperture may be set to asecond aperture width where implant ions into the target at a thirdenergy and a third current. Adjusting implant energy and implant currentusing the electrode assembly and the variable aperture obviates the needto adjust the ion source and extraction assembly conditions, and thusreduces ion beam set up times.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates an exemplary ion implanting system suitable forperforming a multi-energy ion implantation process

FIG. 2 illustrates an exemplary electrode assembly that may be used inperforming a multi-energy ion implantation process.

FIG. 3 illustrates an exemplary process for multi-energy ionimplantation.

DETAILED DESCRIPTION

The following description is presented to enable a person of ordinaryskill in the art to make and use the various embodiments. Descriptionsof specific systems, devices, methods, and applications are providedonly as examples. Various modifications to the examples described hereinwill be readily apparent to those of ordinary skill in the art, and thegeneral principles defined herein may be applied to other examples andapplications without departing from the spirit and scope of the variousembodiments. Thus, the various embodiments are not intended to belimited to the examples described herein and shown, but are to beaccorded the scope consistent with the claims.

1. Ion Implanting System

FIG. 1 depicts an exemplary ion implanting system 100 suitable forperforming a multi-energy ion implantation process on a target 116 inaccordance with various embodiments. The system 100 may include an ionsource 102, an extraction assembly 104, a mass analyzer 108, and anelectrode assembly 112. Ion beam 106 may be generated with ion source102 and extraction assembly 104. Ion source 102 may be, for example, aBernas or a Freeman ion source. Ion source 102 may generate desired ionspecies by the electron ionization of a source gas to form a plasma. Forsemiconductor device fabrication, the desired ion species may includedopant ion species that comprise of boron, phosphorus, or arsenic, suchas, but not limited to B+, P+, and As+. Extraction assembly 104 mayinclude at least one extraction electrode capable of having anextraction voltage applied thereto. An extraction voltage may be appliedto the at least one extraction electrode in extraction assembly 104 toextract ions from ion source 102 and generate ion beam 106. Theextraction voltage is typically a negative voltage relative to the ionsource when generating an ion beam having positive ion species and apositive voltage relative to the ion source when generating an ion beamhaving negative ion species. Ion beam 106 may be generated at a firstenergy and at a first current by ion source 102 and extraction assembly104. The magnitude of the first energy is at least partially determinedby the magnitude of the extraction voltage where a larger extractionvoltage generates an ion beam having a higher energy. The magnitude ofthe first current is at least partially determined by the density of theplasma formed in ion source 102 and the magnitude of the extractionvoltage where a denser plasma and a larger extraction voltage generatesan ion beam having a higher current. The density of the plasma formed inion source 102 is at least partially determined by the source gas flowrate and the arc current.

Ion beam 106 may be directed into mass analyzer unit 108 as shown inFIG. 1. Mass analyzer unit 108 may apply a magnetic field such that onlythe ion species in ion beam 106 having the desired mass-to-charge ratiopass through mass analyzer unit 108. Ion beam 106 may pass through avariable aperture 110 before entering electrode assembly 112. Variableaperture 110 may adjust the ion beam current by varying the aperturewidth through which the ion beam 106 passes. In one example, aperturewidth may be controlled between 0.1mm and 100mm so that the ion beamcurrent may be varied across a range of up to 3 orders of magnitude. Theaperture width of variable aperture may be controlled such that ion beam106 implants target 116 at a second current where the second current islower than the first current at which ion beam 106 is generated. Asmaller aperture width results in a lower ion beam current while alarger aperture width results in a higher ion beam current implantingtarget 116. Variable aperture 110 may be disposed either before or after(not shown) electrode assembly 112. When variable aperture 110 isdisposed after the electrode assembly, it is closer to target 116 andthus the shape of the ion beam and the ion beam current may becontrolled with greater precision. Alternatively, placing variableaperture 110 before electrode assembly 112 reduces particle and energycontamination because electrode assembly 112 may filter out from ionbeam 106 contaminant particles and neutral species generated by variableaperture 110. In yet another example (not shown), an ion implantingsystem may include two variable apertures with the first disposed beforeand the second disposed after the electrode assembly 112.

In one example, variable aperture 110 may act as a shutter. In such anexample, variable aperture 110 may completely close and block ion beam106, thereby preventing ion beam 106 from implanting ions into target116. Ion beam 106 may need to be blocked in between implants when theion beam conditions, such as the extraction voltage or electrodeassembly voltage, are changed. Alternatively, ion implanting system 100may include a separate shutter (not shown) to block ion beam 106.

The energy of the ion beam 106 may remain approximately constant as ittravels from extraction assembly 104 to electrode assembly 112. Forexample, ion beam 106 may enter electrode assembly 112 having an energythat is approximately equal to the first energy at which ion beam 106 isgenerated. A voltage may be applied across electrode assembly 112 tochange the ion beam energy of ion beam 106. In one example, a firstvoltage may be applied across electrode assembly 112 to eitheraccelerate or decelerate ion beam 106. In such an example, ion beam 106may enter electrode assembly 112 at the first energy and exit electrodeassembly 112 at a second energy. The second energy may be different fromthe first energy. If the applied first voltage accelerates ion beam 106,then the second energy is higher than the first energy. If the appliedfirst voltage decelerates ion beam 106, then the second energy is lowerthan the first energy. In another example, a voltage approximately equalto zero may be applied across electrode assembly 112 where ion beam 106passes through electrode assembly 112 without accelerating ordecelerating. In such an example, ion beam 106 may enter electrodeassembly 112 at the first energy and exit electrode assembly 112 atapproximately the first energy.

Ion beam 106 may pass straight through electrode assembly 112 withoutbeing deflected from its original path. Alternatively, electrodeassembly 112 may deflect the path of ion beam 106 as it passes throughelectrode assembly 112. Deflecting the path of the ion beam 106 helps toreduce energy contamination during the implant process. Energycontamination describes the amount of dopant species in the ion beamthat are neutral species and have an energy that is different from thedesired energy. For example, a first voltage may be applied acrosselectrode assembly 112 such that ion beam 106 enters electrode assembly112 at 10 keV and exit electrode assembly at 500 eV. While passingthrough electrode assembly 112, some dopant ions species in ion beam 106may be neutralized as a result of charge exchange from colliding withresidual molecules. In such an example, energy contamination may bedefined as the percentage of dopant species in ion beam 106 exitingelectrode assembly 112 that are neutral species having an energy greaterthan 500 eV. The deflection inside electrode assembly 112 effectivelyblocks and removes almost all neutralized dopant species, therebyreducing energy contamination.

FIG. 2 depicts an exemplary electrode assembly 200 for accelerating ordecelerating an ion beam 206 in an ion implanting system. Electrodeassembly 200 may comprise multiple electrodes 202 that include anentrance electrode 208 and an exit electrode 210. Each electrode 202 maybe capable of having a voltage applied thereto. The voltages applied toeach electrode 202 generate electric fields that are represented byequal potential electric field lines 204 shown in FIG. 2. Ion beam 206may be manipulated by these electric fields and may thus be deflected,accelerated or decelerated as it travels through electrode assembly 200.

The voltage applied across electrode assembly 200 at least partiallydetermines the net acceleration or deceleration of ion beam 206 throughelectrode assembly 200. Applying a negative voltage across electrodeassembly 200 accelerates an ion beam consisting primarily of negativelycharged ion species and decelerates an ion beam consisting primarily ofpositively charged ion species. Conversely, applying a positive voltageacross electrode assembly 200 accelerates an ion beam consistingprimarily of positively charged ion species and decelerates an ion beamconsisting primarily of negatively charged ion species. A positivevoltage is applied across electrode assembly 200 when the voltageapplied to entrance electrode 208 is more positive than the voltageapplied to exit electrode 210. Similarly, a negative voltage is appliedacross electrode assembly 200 when the voltage applied to entranceelectrode 208 is more negative than the voltage applied to exitelectrode. The extent at which ion beam 206 is accelerated ordecelerated through electrode assembly 200 is at least partiallydetermined by the magnitude of the voltage applied across electrodeassembly 200. The larger the magnitude of the voltage, the greater theextent ion beam 206 is accelerated or decelerated through electrodeassembly 200.

Electrodes 202 may be configured to deflect ion beam 206 from itsoriginal path as it passes through electrode assembly 200. For example,as shown in FIG. 2, electrodes 202 may deflect ion beam 206 to follow aS-shaped path while it passes through electrode assembly 200. Deflectingion beam 206 in electrode assembly 200 may help to reduce energycontamination. Energy contamination occurs when neutral speciesgenerated in the ion beam are allowed to pass through the electrodeassembly. These neutral species are generated by collisions andcharge-exchanges due to collisions between the ion species and residualparticles as the ion beam travels from the mass analyzer unit to theelectrode assembly and through the electrode assembly. The neutralspecies are not affected by the electric fields in electrode assembly200 and thus do not accelerate or decelerate through electrode assembly200. Allowing these neutral species to pass through electrode assembly200 would result in these neutral species exiting electrode assembly 200at different energies from the ion species in the ion beam. Whenimplanting a target, the neutral species may implant into the target ata different depth than the ion species and result in an undesired deepertail in the dopant depth profile. In semiconductor device fabrication, adeep tail in the dopant depth profile would produce deeper junctiondepths with undesirable electrical characteristics. Deflecting ion beam206 in electrode assembly 200 helps to filters out neutral species fromion beam 206 because the neutral species are not deflected by theelectric fields and thus may be diverted to a neutral beam dump (notshown). In this way, ion beam 106 may pass through electrode assembly200 with minimal energy contamination.

Referring back to FIG. 1, target 116 may be placed on a holdingapparatus 118 in ion implanting system 100. Target 116 may be any targetin which ions are desired to be implanted. For example, target 116 maybe a semiconductor wafer having a semiconductor structure to beimplanted with dopant ions. Target 116 has an implantation surface inwhich ions are implanted. Holding apparatus 118 may position target 116in ion beam 106 such that ion beam 106 exiting electrode assembly 112 isincident to the implantation surface of target 116, thereby implantingions into the implantation surface of target 116. Holding apparatus mayprovide rotational (tilt and twist) and translational movement of target116 with respect to ion beam 106. The rotational movement may controlthe angle of incidence of ion beam 106 to the implantation surface oftarget 116 and thus the implant angle. The translational movement movestarget 116 and permits ion beam 106 to scan across the implantationsurface of target 116. The velocity of the translational movementcontrols the moving velocity of target 116, which at least partiallydetermines the implant dose in target 116. A faster moving velocityresults in a lower implant dose in target 116.

The energy at which ions are implanted into target 116 may beapproximately equal to the energy of ion beam 106 exiting electrodeassembly 112. For example, ion beam 106 may exit electrode assembly 112at the second energy and then implant ions into target 116 at the secondenergy.

Controller 120 is coupled to the various components of ion implantingsystem 100 and controls the ion implanting system 100 to perform themethods and exemplary processes of multi-energy ion implantation into atarget as described herein. The function and characteristics ofcontroller 120 will be described later in greater detail.

2. Multi-Energy Ion Implantation Process

FIG. 3 depicts an exemplary process 300 for multi-energy ionimplantation into a target. Process 300 may be performed using anysuitable ion implanting system having an ion source, an extractionassembly, and an electrode assembly, such as ion implanting system 100described in FIG. 1. Additionally, the ion implanting system mayoptionally include a variable aperture and a holding apparatus. Inprocess 300, the implant energies and implant currents may be adjustedwithout changing the ion source conditions (e.g., dopant gas flow rate,source magnetic field, arc current) and the extraction assemblyconditions (e.g., extraction voltage, extraction electrode positions).The ion source and extraction assembly conditions may therefore be keptconstant throughout process 300 where implant energies are controlled byadjusting the voltage applied across the electrode assembly and theimplant current is controlled by adjusting the aperture width of thevariable aperture. In this way, the ion beam may be kept stablethroughout process 300, which obviates the need for long tuning andstabilization times (e.g., 3-10 minutes) each time the ion beam energyand current is adjusted. Therefore, the throughput for process 300 maybe significantly higher compared to conventional multi-energy ionimplantation processes.

The target may be, for example, a silicon wafer having semiconductorstructures formed thereon. In one example, the semiconductor structuresmay be semiconductor fins for forming fin field effect transistor(FINFET) devices. Process 300 may enable the uniform doping of thesemiconductor fins to achieve desirable electrical characteristics inthe FINFET devices.

At block 302 of process 300, an ion beam having a first energy and afirst current may be generated using the ion source and the extractionassembly of the ion implanting system. As previously explained in FIG.1, the ion beam may be generated by applying an extraction voltage to atleast one extraction electrode in the extraction assembly to extractions from the ion source. First energy may be as high as the highestdesired implant energy and the first current may be at least as high asthe highest desired implant current required for implanting the targetin process 300. In one example, first energy may be between 2 keV and 30keV and first current may be between 5 mA and 25 mA. In another example,first energy may be between 15 keV and 25 keV and first current may bebetween 10 mA and 20 mA. In yet another example where the ion beamconsists primarily of As+ ion species, the first energy may be 20 keVand the first current may be 15 mA.

At block 304 of process 300, a first voltage may be applied across theelectrode assembly where the ion beam enters the electrode assembly atthe first energy and exits the electrode assembly at the second energy.In one example, the first voltage may be approximately 0V. In such anexample, the ion beam may pass through the electrode assembly withoutaccelerating or decelerating where the second energy is approximatelyequal to the first energy.

In another example, the first voltage may be a positive or a negativevoltage having a magnitude greater than 0V to either accelerate ordecelerate the ion beam. Typically, a negative voltage is applied toeither accelerate an ion beam consisting primarily of negative ionspecies or to decelerate an ion beam consisting primarily of positiveion species. Conversely, a positive voltage is typically applied toeither decelerate an ion beam consisting primarily of negative ionspecies or to accelerate an ion beam consisting primarily of positiveion species. In one example, the magnitude of the first voltage may bebetween 0 kV and 30 kV. In another example, the magnitude of the firstvoltage may be between 10 kV and 20 kV. While applying the firstvoltage, the ion beam may enter the electrode assembly at approximatelythe first energy, accelerate or decelerate in the electrode assembly,and exit the electrode assembly at a second energy. The second energymay be different from the first energy. The accelerated or deceleratedion beam may then be directed to the target and implant ions into thetarget at the second energy. In one example, the second energy may bebetween 0.05 keV and 30 keV. In another example, the second energy maybe between 0.2 keV and 10 keV. In an example where the applied firstvoltage decelerates the ion beam, the second energy is lower than thefirst energy. In one such example, the ion beam may consist primarily ofAs+ ion species, the first voltage may be −15 kV, the first energy maybe 20 keV, and the second energy may be 5 keV. In an example where theapplied first voltage accelerates the ion beam in the electrodeassembly, the second energy is higher than the first energy. In one suchexample, the ion beam may consist primarily of As+ ion species, thefirst voltage may be +10 kV, the first energy may be 20 keV, and thesecond energy may be 30 keV.

In one example, the applied first voltage may be such that the ion beamexiting the electrode assembly has an ion beam current that is notsuitable to achieve the desired implant dose in the target. In such anexample, the variable aperture may be controlled to adjust the ion beamcurrent in order to achieve the desired implant dose. The variableaperture may be set to a first aperture width to achieve the desired ionbeam current. For example, the first aperture width may be between 0.1mm and 100 mm. The first aperture width may be sufficient to achieve anion beam current where ions are implanted into the target at a secondcurrent. In one example, the first aperture width may be such that theion beam current reduces when the ion beam passes through the variableaperture. In one such example, the ion beam may exit the variableaperture having a current lower than the first current. In anotherexample, the first aperture width may be such that the ion beam currentis unchanged when the ion beam passes through the variable aperture. Thesecond current may be lower than the first current. In one example, thesecond current may be between 0.001 mA and 40 mA. In another example,the second current may be between 5 mA and 15 mA while the first currentmay be between 5 mA and 25 mA.

Additionally, the moving velocity of the target may be controlled duringimplanting to achieve the required implant dose in the target. Themoving velocity of the target may be adjusted by controlling thetranslational movement of the holding apparatus. In one example, themoving velocity of the target may be set to a first velocity while theion beam implants ions into the target at the second energy. The firstvelocity may be sufficient to achieve the required implant dose in thetarget. The first moving velocity may be between 10 mm/s and 2000 mm/s.

At block 306 of process 300, a second voltage may be applied across theelectrode assembly to accelerate or decelerate the ion beam. The secondvoltage may be 0V. Alternatively, the second voltage may be a non-zeropositive voltage, or negative voltage. The second voltage may bedifferent from the first voltage. In one example, the magnitude of thesecond voltage may be between 0 kV and 30 kV. In another example, themagnitude of the second voltage may be between 10 kV and 20 kV. Whileapplying the second voltage, the ion beam may enter the electrodeassembly at approximately the first energy and exit the electrodeassembly at a third energy. The ion beam may then be directed to thetarget and implants ions into the target at the third energy. In theexample where the second voltage is 0V, the third energy isapproximately equal to the first energy. In the example where theapplied second voltage accelerates the ion beam through the electrodeassembly, the third energy is greater than the first energy. In theexample where the applied second voltage decelerates the ion beamthrough the electrode assembly, the third energy is lower than the firstenergy. The third energy may be different from the second energy. Forexample, the third energy may be higher or lower than the second energy.In one example, third energy may be between 0.05 keV and 30 keV. Inanother example, third energy may be between 0.2 keV and 10 keV. In yetanother example, the ion beam may comprise As+ ion species, the secondvoltage may be −19 kV, the first energy may be 20 keV, and the thirdenergy may be 1 keV.

In one example, the applied second voltage may be such that the ion beamexiting the electrode assembly has an ion beam current that is notsuitable to achieve the desired implant dose in the target. In such anexample, the variable aperture may be controlled to adjust the ion beamcurrent in order to achieve the desired implant dose. The variableaperture may be set to a second aperture width to achieve the desiredion beam current. For example, the second aperture width may be between0.1 mm and 100 mm. The second aperture width may be different from thefirst aperture width. The second aperture width may be sufficient toachieve an ion beam current where ions are implanted into the target ata third current. In one example, the second aperture width may be suchthat the ion beam current reduces when the ion beam passes through thevariable aperture. In one such example, the ion beam may exit thevariable aperture having a current lower than the first current. Inanother example, the second aperture width may be such that the ion beamcurrent is unchanged when the ion beam passes through the variableaperture. The third current may be lower than the first current.Additionally, the third current may be different from the secondcurrent. In one example, the third current may be between 0.001 mA and40 mA. In another example, the third current may be between 0.2 mA and 5mA while the first current may be between 5 mA and 25 mA.

Additionally, the moving velocity of the target may also be controlledduring implanting to achieve the required implant dose in the target.The moving velocity of the target may be adjusted by controlling thetranslational movement of the holding apparatus. In one example, themoving velocity of the target may be set to a second velocity while theion beam implants ions into the target at the third energy. With givenion beam current, the second velocity may be sufficient to achieve therequired implant dose in the target at a predefined scan number (howmany times the wafer moves across the ion beam). The second movingvelocity may be different from the first moving velocity. The secondmoving velocity may be between 50 mm/s and 1000 mm/s.

It should be appreciated that process 300 may include additional ionimplants (not shown) performed at different implant energies. Forexample, a third voltage may be applied across the electrode assembly toaccelerate or decelerate the ion beam. The ion beam may enter theelectrode assembly at approximately the first energy, accelerate ordecelerate in the electrode assembly, and exit the electrode assembly ata fourth energy. The ion beam exiting the electrode assembly may thenimplant ions into the target at the fourth energy. The fourth energy maybe different from the third energy.

As previously described, the implant energy in process 300 may becontrolled by only adjusting the voltage while keeping the ion sourceand extraction assembly conditions constant. For example, the ion sourceand extraction assembly conditions in blocks 304 and 306 may be kept atthe same conditions as in block 302 of generating the ion beam. In thisway, the ion beam remains stable. Thus, unlike conventional processes,changing the ion beam energy does not require several minutes to re-tunethe ion beam and wait for it to stabilize. Rather, the ion beam energymany be change quickly where the ion beam may implant ions into thetarget shortly (e.g., <10 seconds or <30 seconds) after changing the ionbeam energy. For example, block 306 may be performed subsequent to block304 where the voltage applied across the electrode assembly is changedfrom the first voltage in block 304 to the second voltage in block 306.As a result, the energy of the ion beam exiting the electrode assemblychanges from the second energy in block 304 to the third energy in block306. The second voltage in block 306 may be applied immediately (e.g.,within 1 second) after implanting of the target at the second energy iscompleted in block 304. The target may then be implanted at the thirdenergy in block 306 within 5-30 seconds of applying the second voltage.Thus process 300 allows for greater throughput compared to conventionalmulti-energy ion implantation processes.

Additionally, because the target may be implanted shortly after changingthe ion beam energy, it obviates the need to implant each target (e.g.,semiconductor wafer) in a production lot at one energy before changingthe ion beam to the next energy. The target thus does not need to beremoved from the ion implanting system between each implant. In oneexample, the target may be disposed on a holding apparatus in the ionimplanting system during process 300. The target may remain on theholding apparatus during and between each implant. For example, thetarget may remain on the holding apparatus during and between blocks 304and 306 of implanting at the second energy and at the third energy. Thisreduces target handling times and thus allows for greater throughput.

As previous described in FIG. 2, the electrode assembly used in process300 may be configured to deflect the ion beam and thus reduce energycontamination. In one example, the ion beam may be deflected in theelectrode assembly in blocks 304 and 306 such that the decelerated ionbeam exits the electrode assembly having an energy contamination of lessthan 0.05%.

3. Computer Implementation

Referring back to FIG. 1, ion implanting system 100 may have acontroller 120. Controller 120 is coupled to the various components andcontrols the ion implanting system 100 to perform the methods andexemplary processes described herein. For example, controller 120 maycontrol the conditions of ion source 102 and extraction assembly 104 togenerate ion beam 106 having a first energy and a first current.Controller 120 may control a variable power source (not shown) to applya voltage across electrode assembly 112. Controller 120 may also controlthe aperture width of variable aperture 110 to control the ion beamcurrent. Additionally, controller 120 may control the rotational andtranslational movement of holding apparatus 118 to position target 116in ion beam 106 such that ion beam 106 is incident to the implantationsurface of target 116 and implants ions into target 116. Controller 120may also control the rotational and translational movement of holdingapparatus 118 to control the moving velocity of target 116.

Controller 120 may be one of any form of general purpose data processingsystem that can be used for controlling the various components of ionimplanting system 100. Generally, controller 120 may include a processor122 in communication with a main memory 124, a storage medium 126, andsupporting devices 128 through a bus 130. Processor 122 may be one ormore general-purpose processing devices such as a microprocessor, acentral processing unit (CPU), or the like. Main memory 124 may berandom access memory (RAM) or any other dynamic memory for transientstorage of information and instructions to be executed by processor 122.Storage medium 126 may include any non-transitory computer-readablestorage medium capable of storing computer software, instructions, ordata, such as, but not limited to a hard disk, a floppy disk, a magnetictape, an optical disk, read only memory (ROM) or other removable orfixed media. The supporting devices 128 may include input/outputinterfaces or communication interfaces such as USB ports, networkinterface, Ethernet, PCMCIA slot, etc.). The supporting devices 128 mayallow computer programs, software, data, or other instructions to beloaded into controller 120 and be provided to processor 122 forexecution.

Non-transitory computer-readable storage medium, such as, storage medium126, or any other suitable media internal or external to controller 120may contain computer executable instructions (generally referred to as“computer program code” which may be grouped in the form of computerprograms or other groupings) for performing any one or more features orfunctions of the processes of multi-energy ion implantation describedherein. One or more of such computer executable instruction, whenprovided to processor 122 for execution, may cause the controller 120 tocontrol ion implanting system 100 to perform any one or more features orfunctions of the multi-energy ion implantation processes describedherein.

While specific components, configurations, features, and functions areprovided above, it will be appreciated by one of ordinary skill in theart that other variations may be used. Additionally, although a featuremay appear to be described in connection with a particular embodiment,one skilled in the art would recognize that various features of thedescribed embodiments may be combined. Moreover, aspects described inconnection with an embodiment may stand alone.

Although embodiments have been fully described with reference to theaccompanying drawings, it is to be noted that various changes andmodifications will become apparent to those skilled in the art. Suchchanges and modifications are to be understood as being included withinthe scope of the various embodiments as defined by the appended claims.

What is claimed is:
 1. A method for multi-energy ion implantation into atarget using an ion implanting system, the ion implanting system havingan ion source, an extraction assembly, and an electrode assembly, themethod comprising: generating an ion beam using the ion source and theextraction assembly, wherein the ion source operates under a set of ionsource conditions and the extraction assembly operates under a set ofextraction assembly conditions to generate the ion beam; applying afirst voltage across the electrode assembly, wherein the ion beam exitsthe electrode assembly at a first energy; positioning the target in theion beam to implant ions into the target at the first energy, whereinthe ion source operates under the set of ion source conditions and theextraction assembly operates under the set extraction conditions whilethe first voltage is applied across the electrode assembly and whileions are implanted into the target at the first energy; applying asecond voltage across the electrode assembly, wherein the ion beam exitsthe electrode assembly at a second energy that is different from thefirst energy; and positioning the target in the ion beam to implant ionsinto the target at the second energy, wherein the ion source operatesunder the set of ion source conditions and the extraction assemblyoperates under the set of extraction conditions while the second voltageis applied across the electrode assembly and while ions are implantedinto the target at the second energy.
 2. The method of claim 1, whereinthe first voltage is approximately zero, and wherein the ion beam entersthe electrode assembly at the first energy and passes through theelectrode assembly before exiting the electrode assembly at the firstenergy.
 3. The method of claim 1, wherein the first voltage is appliedacross the electrode assembly such that the ion beam accelerates as theion beam passes through the electrode assembly before exiting theelectrode assembly at the first energy.
 4. The method of claim 1,wherein the first voltage is applied across the electrode assembly suchthat the ion beam decelerates as the ion beam passes through theelectrode assembly before exiting the electrode assembly at the firstenergy.
 5. The method of claim 1, wherein the second energy is lowerthan the first energy.
 6. The method of claim 1, wherein the secondenergy is higher than the first energy.
 7. The method of claim 1,wherein the target is positioned in the ion beam to implant ions intothe target at the second energy within 30 seconds after the secondvoltage is applied across the electrode assembly.
 8. The method of claim1, further comprising: applying a third voltage across the electrodeassembly, wherein the ion beam exits the electrode assembly at a thirdenergy that is different from the second energy and the first energy;and positioning the target in the ion beam to implant ions into thetarget at the third energy, wherein the ion source operates under theset of ion source conditions and the extraction assembly operates underthe set extraction conditions while the third voltage is applied acrossthe electrode assembly and while ions are implanted into the target atthe third energy.
 9. The method of claim 1, wherein the target isdisposed on a holding apparatus of the ion implanting system, andwherein the target remains on the holding apparatus during and betweenpositioning the target in the ion beam to implant ions into the targetat the first energy and positioning the target in the ion beam toimplant ions into the target at the second energy.
 10. The method ofclaim 1, wherein positioning the target in the ion beam to implant ionsinto the target at the first energy includes translating the target at afirst velocity with respect to the ion beam, wherein positioning thetarget in the ion beam to implant ions into the target at the secondenergy includes translating the target at a second velocity with respectto the ion beam, and wherein the first velocity is different from thesecond velocity.
 11. The method of claim 1, wherein the ion implantingsystem includes a variable aperture, and further comprising: controllingan aperture width of the variable aperture such that the ion beamimplants ions into the target at a first current while the target ispositioned in the ion beam to implant ions into the target at the firstenergy; and controlling the aperture width of the variable aperture suchthat the ion beam implants ions into the target at a second currentwhile the target is positioned in the ion beam to implant ions into thetarget at the second energy, and wherein the second current is differentfrom the first current.
 12. A non-transitory computer-readable storagemedium containing computer executable instructions for multi-energy ionimplantation into a target using an ion implanting system, the ionimplanting system having an ion source, an extraction assembly, and anelectrode assembly, the computer executable instructions comprisinginstructions for: generating an ion beam using the ion source and theextraction assembly, wherein the ion source operates under a set of ionsource conditions and the extraction assembly operates under a set ofextraction assembly conditions to generate the ion beam; applying afirst voltage across the electrode assembly, wherein the ion beam exitsthe electrode assembly at a first energy; positioning the target in theion beam to implant ions into the target at the first energy, whereinthe ion source operates under the set of ion source conditions and theextraction assembly operates under the set extraction conditions whilethe first voltage is applied across the electrode assembly and whileions are implanted into the target at the first energy; applying asecond voltage across the electrode assembly, wherein the ion beam exitsthe electrode assembly at a second energy that is different from thefirst energy; and positioning the target in the ion beam to implant ionsinto the target at the second energy, wherein the ion source operatesunder the set of ion source conditions and the extraction assemblyoperates under the set of extraction conditions while the second voltageis applied across the electrode assembly and while ions are implantedinto the target at the second energy.
 13. The non-transitorycomputer-readable storage medium of claim 12, wherein the target ispositioned in the ion beam to implant ions into the target at the secondenergy within 30 seconds after the second voltage is applied across theelectrode assembly.
 14. The non-transitory computer-readable storagemedium of claim 12, wherein positioning the target in the ion beam toimplant ions into the target at the first energy includes translatingthe target at a first velocity with respect to the ion beam, whereinpositioning the target in the ion beam to implant ions into the targetat the second energy includes translating the target at a secondvelocity with respect to the ion beam, and wherein the first velocity isdifferent from the second velocity.
 15. The non-transitorycomputer-readable storage medium of claim 12, wherein the ion implantingsystem includes a variable aperture, and wherein the computer executableinstructions further comprise instructions for: controlling an aperturewidth of the variable aperture such that the ion beam implants ions intothe target at a first current while the target is positioned in the ionbeam to implant ions into the target at the first energy; andcontrolling the aperture width of the variable aperture such that theion beam implants ions into the target at a second current while thetarget is positioned in the ion beam to implant ions into the target atthe second energy, and wherein the second current is different from thefirst current.
 16. The non-transitory computer-readable storage mediumof claim 12, wherein the computer executable instructions furthercomprise instructions for: deflecting the ion beam as the ion beamtravels through the electrode assembly before exiting the electrodeassembly at the first energy.
 17. The method of claim 1, wherein the ionbeam travels through the electrode assembly prior to exiting theelectrode assembly at the first energy or the second energy, and whereinthe ion beam is deflected as the ion beam travels through the electrodeassembly.
 18. The method of claim 17, wherein the ion beam is deflectedalong an S-shaped path as the ion beam travels through the electrodeassembly.
 19. The method of claim 17, wherein the ion beam exits theelectrode assembly having an energy contamination of less than 0.05%.20. The method of claim 1, wherein: the target includes a fin fieldeffect transistor device at least partially formed thereon; the targetis positioned in the ion beam to implant ions into the at leastpartially formed fin field effect transistor device at the first energy;and the target is positioned in the ion beam to implant ions into the atleast partially formed fin field effect transistor device at the secondenergy.